用JSP从数据库中读取图片并显示在网页上

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环境：mysql+tomcat:

<1>先在mysql下建立如下的table. 并insert图像.
mysql.sql文件如下:

CREATE TABLE photo ( photo_no int(6) unsigned NOT NULL auto_increment, image blob, PRIMARY KEY (`photo_no`) )

<2>把show.jsp放在tomcat的任意目录下. show.jsp作用:从数据库中读出blob,并产生image/jpg.

show.jsp文件如下:

<%@ page contentType="text/html; charset=gbk" %> <%@ page import="java.io.*"%> <%@ page import="java.sql.*, javax.sql.*" %> <%@ page import="java.util.*"%> <%@ page import="java.math.*"%> <% String photo_no = request.getParameter("photo_no"); //mysql连接 Class.forName("com.mysql.jdbc.Driver").newInstance(); String URL="jdbc:mysql://localhost:3306/job?user=root&password=111111"; Connection con = DriverManager.getConnection(URL); //oracle连接 //String URL="jdbc:oracle:thin@localhost:1521:orcl2"; //user="system"; //password="manager"; //Connection con = DriverManager.getConnection(URL,user,password); try{ // 准备语句执行对象 Statement stmt = con.createStatement(); String sql = " SELECT * FROM PHOTO WHERE photo_no = "+ photo_no; ResultSet rs = stmt.executeQuery(sql); if (rs.next()) { Blob b = rs.getBlob("photo_image"); long size = b.length(); //out.print(size); byte[] bs = b.getBytes(1, (int)size); response.setContentType("image/jpeg"); OutputStream outs = response.getOutputStream(); outs.write(bs); outs.flush(); rs.close(); } else { rs.close(); response.sendRedirect("./images/error.gif"); } } finally{ con.close(); } %>

<3>把如下文件放在show.jsp的同一目录下.
index.html文件如下:

<html><head><title> 图像测试 </title></head><body><table><tr><td>图像测试</td></tr><tr><td><img src="show.jsp?photo_no=2"></td></tr></table></body></html>

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